This
is a very large family of nocturnal moths that come in a wide variety
of sizes with wingspans ranging from 12 to 120 millimetres. All
geometrids have a uniform shape and stance, which is characteristic
of the family. The forewings of these moths are broad and triangular
in shape with hind wings almost as broad. During the day all geometrids
hold their wings outstretched and flat against the surface they
are resting on, with the top of the forewing forming an almost straight
line at right angles to the body. Many adults are green in colour,
often with mottled patterns which when combined with their posture
allows them to blend with their surroundings, making them very cryptic.

Geometrid
caterpillars are known as loopers due to their method of locomotion. Unlike
other caterpillars, geometrid larvae have a gap between their thoracic
legs and their prolegs at the end of the abdomen and as a result move
by a series of loops. The front of the body is stretched out and held
in place with the 3 pairs of true legs and then the back of the body is
brought forward so the prolegs at the rear can grasp the surface near
the front legs. These caterpillars are often also called 'inchworms' because
of this motion and the scientific name of this family means 'earth measurers'.

Phallaria
ophiusaria (brown
leaf moth)

Geometrid
caterpillars are plant feeders and can often be seen during
the day mimicking twigs by remaining erect supported by their
prolegs among the foliage of their food plant.

This
species can be found during the day resting motionless on wattles
(Acacia species), hopbush (Dodonaea species) and
Hakea species, looking much like a dead twig.

For
more looper species visit the Australian
Insect Common
Names
- Geometridae section found here.